Electronic device including a patch antenna and photovoltaic layer and related methods

ABSTRACT

An electronic device may include a substrate and a stacked arrangement of layers thereon. The stacked arrangement of layers may include a photovoltaic layer above the substrate, and an antenna ground plane above the photovoltaic layer. The antenna ground plane may include a first electrically conductive mesh layer being optically transmissive. The stacked arrangement of layers may further include a patch antenna above the photovoltaic layer and may include a second electrically conductive mesh layer being optically transmissive.

FIELD OF THE INVENTION

The present invention relates to the field of electronic devices, and,more particularly, to electronic devices including antennas and relatedmethods.

BACKGROUND OF THE INVENTION

Antennas may be used for a variety of purposes, such as communicationsor navigation, and wireless devices may include broadcast receivers,pagers, or radio location devices (“ID tags”). The cellular telephone isan example of a wireless communications device, which is nearlyubiquitous. A relatively small size, increased efficiency, and arelatively broad radiation pattern are generally desired characteristicsof an antenna for a portable radio or wireless device.

Additionally, as the functionality of a wireless device continues toincrease, so too does the demand for a smaller wireless device which iseasier and more convenient for a user to carry, yet uses relatively lesspower and/or has a longer standby time. One challenge this poses forwireless device manufacturers is designing antennas that provide desiredoperating characteristics within the relatively limited amount of spaceavailable for antennas, and that cooperate with related circuitry to usea reduced amount of power. For example, it may be desirable for anantenna to communicate at a given frequency with desiredcharacteristics, such as bandwidth, polarization, gain pattern, andradiation pattern, for example, and for the wireless device to beoperational for several days on a single battery or charge cycle.

It may be desirable that a personal communications device, for example,a cellular telephone, be relatively small in size. In other words, itmay be desirable that the device volume and surface area are relativelylimited. This, in turn, may result in size and performance tradesbetween components, for example, having a relatively large battery maymean having a relatively small antenna. Compound designs may be desiredto improve component integration.

The electrical power requirements of an electronic device, for example,have generally been reduced. For example, the field effect semiconductorhas allowed even solar powered electronics to become increasinglypopular. The solar cell may require increased product surface areahowever, which may be required for other purposes, for example, akeyboard.

Many antennas may include a combination of relatively good conductorsand relatively good insulators for efficiency, for example. This may beparticularly so in a microstrip patch antenna, for example, as strongnear field reactive energies circulate in the printed wire boarddielectric, which may cause heating losses. A solar cell which includessemiconductors, for example, are neither relatively good conductors norrelatively good insulators.

To achieve desired antenna characteristics, the size and shape of anantenna, for example, a patch antenna may be adjusted. For example, U.S.Patent Application Publication No. 2010/0103049 to Tabakovic discloses apatch antenna having a patch antenna element and a conductive layer anddual separated feeds coupled thereto. Each of the dual feeds has aconductor segment and a deltoid shaped conductive strip orthogonal tothe conductor segment. U.S. Patent Application Publication No.2009/0051598 to McCarrick et al. discloses a patch antenna having asolid geometry, for example, square, polygon, ellipse, oval, semicircle,and deltoid.

To reduce power consumption, the functionality of a photovoltaic cellmay be combined with an antenna. For example, U.S. Pat. No. 6,590,150 toKiefer attempts to combine the functionality of a photovoltaic cell andan antenna in a single unit. More particularly, Kiefer discloses a gridor front electrical contact, an anti-reflective coating, twosemiconductor layers, a dielectric layer, and a ground plane layerconfigured in a stacked arrangement.

In an attempt to further provide space savings, several approachesdisclose using a display and an antenna in a stacked relation. Forexample, U.S. Pat. No. 6,697,020 to Xing discloses an integratedmulti-layer structure for a portable communications device that includesan antenna coupled between an LCD display and dielectric substrate. U.S.Pat. No. 6,774,847 to Epstein et al. discloses a chip antenna, a rigidprinted circuit, a conductive material, a lens material, and a displaycoupled in a stacked arrangement.

SUMMARY OF THE INVENTION

In view of the foregoing background, it is therefore an object of thepresent invention to provide an electronic device that includes a patchantenna that provides desired operating characteristics and has areduced size and cooperates with a photovoltaic layer.

This and other objects, features, and advantages in accordance with thepresent invention are provided by an electronic device that includes asubstrate and a stacked arrangement of layers thereon. The stackedarrangement of layers includes a photovoltaic layer above the substrate,and an antenna ground plane above the photovoltaic layer. The antennaground plane includes a first electrically conductive mesh layer beingoptically transmissive. The stacked arrangement of layers also includesa patch antenna above the photovoltaic layer and includes a secondelectrically conductive mesh layer being optically transmissive.Accordingly, the electronic device includes an optically transmissivepatch antenna that cooperates with the photovoltaic layer and providesdesired operating characteristics.

The electronic device may further include wireless circuitry powered bythe photovoltaic layer and coupled to the patch antenna, for example.The electronic device may also include a dielectric layer between theantenna ground plane and the patch antenna. The dielectric layer may beoptically transmissive, for example. The electronic device may furtherinclude at least one anti-reflective layer on the dielectric layer.

The patch antenna may have a perimeter defined by a plurality ofperimeter segments comprising at least one pair of arcuate perimetersegments with a cusp therebetween. The at least one pair of arcuateperimeter segments may be inwardly extending, for example.

The patch antenna may be planar, for example. The electronic device mayfurther include at least one antenna feed coupled to the patch antenna.The at least one antenna feed may include a pair of antenna feeds for anon-linear polarization, for example.

The second electrically conductive mesh layer may be a flexibleinterwoven electrically conductive mesh layer. The second electricallyconductive mesh layer may include a body portion and a hem portioncoupled thereto, for example.

A method aspect is directed to a method of making an electronic device.The method includes forming a stacked arrangement of layers on asubstrate by at least. positioning a photovoltaic layer above thesubstrate, and positioning an antenna ground plane above thephotovoltaic layer. The ground plane includes a first electricallyconductive mesh layer that is optically transmissive. Forming thestacked arrangement of layers also includes positioning a patch antennaabove the photovoltaic layer. The patch antenna includes a secondelectrically conductive mesh layer that is also optically transmissive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a portion of an electronic device inaccordance with the present invention.

FIG. 2 is an enlarged cross-sectional view of a portion of theelectronic device in FIG. 1 taken along the line 2-2.

FIG. 3 is graph illustrating the relationship of between a circularshape antenna and the shape of the patch antenna of FIG. 1.

FIG. 4 is a perspective exploded view of a portion of another embodimentof an electronic device in accordance with the present invention.

FIG. 5 is an enlarged cross-sectional view of a portion of theelectronic device in FIG. 4 taken along the line 5-5.

FIG. 6 is a top view of another embodiment of an electronic device inaccordance with the present invention.

FIG. 7 is a perspective exploded view of a portion of the electronicdevice in FIG. 6.

FIG. 8 is a graph of measured impedance of a prototype electronic devicein accordance with the present invention.

FIG. 9 is a graph of measured voltage standing wave ratio of theprototype electronic device.

FIG. 10 is a graph of measured gain of the prototype electronic device.

FIG. 11 is a graph of a calculated radiation pattern of the prototypeelectronic device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. This invention may, however, be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Likenumbers refer to like elements throughout, and prime and multiplenotation is used to indicate similar elements in alternativeembodiments.

Referring initially to FIGS. 1-3, an electronic device 20 illustrativelyincludes a housing 31. The electronic device also includes circuitry 34carried by the housing 31. The electronic device 20 also includes inputdevices 33 and a display 32 carried by the housing 31. The circuitry 34also includes a power divider 38 a receiver and/or transmitter 37coupled thereto.

The circuitry 34 includes a controller 35 that is coupled to the display32 and input devices 33, and is carried by the housing 31. Of course,the electronic device 20 may not include a display 32 and/or inputdevices 33, for example, if the circuitry is configured to perform atleast one geo-location function or other function where these componentsmay not be desired. The controller 35 may perform at least one wirelesscommunications function. For example, the electronic device 20 may be acellular telephone, and the controller 35 may cooperate with thereceiver and/or transmitter 37 to communicate with a cellular basestation. Of course, the electronic device 20 may be another type ofdevice, for example, a two-way radio or a satellite receiver. Thecontroller 35 may cooperate with the receiver and/or transmitter 37 toperform either or both of a receive and transmit function.

The electronic device 20 illustratively includes a substrate 21. Thesubstrate may be a circuit board, such as, for example, a printedcircuit board (PCB). In some embodiments, the substrate 21 may be thedevice housing 31.

The substrate 21 may be made of a material having permittivity andpermeability within ±50% of each other to increase light transmissiontherethrough. It may be preferred that the substrate material may have apermittivity and a permeability within ±10% of each other. This mayreduce loss of light transmission due to reflections, for example.Permittivity and permeability being within ±50% of each other in thesubstrate 21 may reduce the reflections to the air which can increasepower production in a solar power embodiment, for example.

This may be shown mathematically. The reflection coefficient at the airto substrate interface is a function of the characteristic impedances ofthe air and substrate 21 according to:

Γ(η_(substrate 21)−η_(air))(η_(substrate 21)+η_(air))  (equation 1)

Where:

Γ=the reflection coefficient, a dimensionless number between 0 and 1,preferentially 0 for the substrate 21,η₁=the wave impedance in the substrate in ohms, andη₂=the wave impedance in the air=377 ohms.In turn the wave impedance in the air or substrate 21 may be calculatedaccording to:

η=120π√(μ_(r)/∈_(r))  (equation 2)

where:μ_(r)=the relative magnetic permability of the air or substrate, and∈_(r)=the relative dielectric permeability of the air or substrate.Zero reflection and increased light transmission occurs when μ_(r)=∈_(r)in the substrate 21 since this condition causesη_(substrate)=120π=η_(air) in equation 2. As can be appreciated inequation 1 when η_(substrate)=η_(air) the numerator is 0 which meansequation 1 is 0, which thus means there is no reflection.

The electronic device 20 also includes a patch antenna 40 carried by thesubstrate 21. The patch antenna 40 includes an electrically conductivemesh layer 41 having a perimeter defining four arcuate perimetersegments 42 a-42 d. A respective cusp 43 a-43 d is between each of thefour arcuate perimeter segments. Each of the four arcuate perimetersegments 42 a-42 d is illustratively extending inwardly. Of course, notall the perimeter segments 42 a-42 d may be arcuate, and not all theperimeter segments may extend inwardly. For example, a single pair ofsegments may be arcuate. Additionally, while four perimeter segments areillustrated, the patch antenna 40 may include two or more perimetersegments. Indeed, as will be appreciated by those skilled in the art,the shape of the electrically conductive mesh layer 41 may be describedas resembling a hypocycloid. A hypocycloid shape may include a deltoidshape and an astroid, for example.

Inward or outward adjustment of the arcuate perimeter segments 42 a-42 dchanges the frequency. In other words, the frequency is dependent on theoverall size of the patch antenna 40. For broadside radiation, theperimeter may correspond to 360-degrees guided wavelength, which mayalso correspond to the forced resonance or 1 wavelength of the desiredoperating frequency, for example, in a dielectric printed wire board. Anapproximate formula for the circumference of an embodiment providingbroadside radiation is:

C=c/(f√μ _(r)∈_(r))

Where:

C=circumference of the patch antenna 40c=speed of lightf=operating frequency in Hertzμ_(r)=substrate relative magnetic permeability∈_(r)=substrate relative dielectric permittivity

An increase in the diameter a decreases the operating frequency whichalso reduces antenna size (FIG. 3). This is because current through thepatch antenna 40 has a longer path to curl around the periphery for sucha shape.

Advantageously, frequency may be adjusted without changing the envelopeof the patch antenna 40, thus maintaining a smaller patch antenna. Aswill be appreciated by those skilled in the art, the shape of the patchantenna 40 assumes antenna properties of both linear (rectangular) andcircular patch antennas. In other words, by adjusting the shape of thepatch antenna 40, there is a continuous trade-off of divergence andcurl, and antenna properties between patch antennas, such as, forexample, size, frequency, and beam width. This relationship isillustrated more particularly in FIG. 3, whereinx^(2/3)+y^(2/3)=a^(2/3), x=a cos³ f, and y=a sin³ f, which is theequation of the hypocycloid. The hypocycloid equation advantageouslyprovides variation in the shape of the patch antenna 40 to form hybridsbetween the dipole turnstile (X shape) and loop (circle shape) patchantennas. For example, a concave arcuate patch embodiment has greaterbeamwidth than a convex arcuate embodiment and vice versa. The convexarcuate embodiment has more gain for area than a concave arcuateembodiment and vice versa.

The electrically conductive mesh layer 41 is also flexible. In otherwords, the electrically conductive mesh layer 41 may be contoured, forexample, to the housing 31, substrate 21, or other structure, as will beappreciated by those skilled in the art. Additionally, theelectronically conductive mesh layer 41 may also be interwoven.

The electrically conductive mesh layer 41 also includes a hem portion48, which is coupled to a body portion. The hem portion 48, or solidborder advantageously increases the overall strength of the patchantenna and flattens the Chebyshev response. More particularly, the hemportion 48 may make the Cheybshev response symmetrical about thepolynomial zeroes.

The electrically conductive mesh layer 41 includes a metallic material,for example, molybdenum and gold. Further details of the electricallyconductive mesh layer 41 may be found in U.S. Pat. Nos. 4,609,923 and4,812,854, both to Boan et al., both of which are assigned to theassignee of the present application, and both of which are incorporatedin their entirety by reference.

It may be particularly advantageous to reduce the diameter of theconductors forming the electrically conductive mesh layer 41 to increasetransparency, for example. An example conductor width corresponds to theradio frequency skin depth which is given by:

W=√(2ρ/ωμ)

Where:

w=mesh conductor widthρ=resistivity of mesh conductorω=angular frequency=2πfμ=magnetic permeability of mesh conductorAs an example, for copper conductors at 1 GHz, a desired conductor widthcalculates to be 2.1×10⁻⁶ meters. Thus, relatively fine width meshconductors may be particularly advantageous for improved displayvisibility, for example.

The patch antenna 40 is illustratively planar. Indeed, while the patchantenna 40 being planar may be particularly advantageous for increasedspace savings in a limited space housing 31, for example, the patchantenna, in some embodiments (not shown), may not be planar.

The electronic device 20 also includes an antenna ground plane 51between the substrate 21 and the patch antenna 40. The antenna groundplane 51 may be a conductive layer carried by the substrate 21 or PCB,and the antenna ground plane is preferentially optically transparent,for example, a relatively fine mesh. The substrate or PCB 21 may includethe antenna ground plane 51 or it may be separate therefrom. Adielectric layer 52 is also between the antenna ground plane 51 and thepatch antenna 40. An antenna ground plane material may be a conductivefabric, such as, for example, described in U.S. Pat. Nos. 4,609,923 and4,812,854, both to Boan et al, as noted above. The substrate 21 may becoated with antireflection coatings (not shown) to increase lighttransmission through the dielectric layer 52, for example.Antireflective coatings may be used with other layers.

A pair of antenna feeds 44 is coupled to the patch antenna. The pair ofantenna feeds 44 are also coupled to the circuitry 32, and moreparticularly, to the power divider 38. The power divider 38 is azero-degree power divider, but may be another type of power divider. Thepair of antenna feeds 44 is illustratively coaxial cable feeds. Each ofthe coaxial cable feeds 44 a, 44 b, has a respective inner and outerconductor 45, 46 separated by a dielectric layer 47. The inner conductor45, or drive pin, of each of the coaxial cables 44 a, 44 b passesthrough the ground plane 51 and couples to the patch antenna 40. Theouter conductors 46 are coupled to the ground plane 51.

Each coaxial cable feed 44 a, 44 b coupled between the electricallyconductive mesh layer 41 and the power divider 38 may be a differentlength. The different lengths advantageously introduce a 90-degreealternating current (AC) phase different (i.e. a time delay) into thesignal. Thus, the signal has a circular, or non-linear, polarization. Insome embodiments, a single antenna feed may be used, and thus, thesignal would have a linear polarization.

The first coaxial cable 44 a is coupled to the electrically conductivemesh layer 41 at a first location, while the second coaxial cable 44 bis coupled to the antenna at a second location that is diagonal from thefirst location with respect to the electrically conductive mesh layer41. The position of the first and second locations determines impedance,which in the illustrated example, is about 50 ohms. The angular positionof the antenna feeds 44 a, 44 b determines the polarization angle andorientation angle. More particularly, if a sine wave, for example, isapplied to the first antenna feed 44 a, because of the length differenceof the coaxial cables, or antenna feeds, a cosine wave may be applied atthe second location. This arrangement provides the circular polarizationof a transmitted signal, for example. Indeed, while the antenna feeds 44a, 44 b are illustratively coaxial cables, they may be other types ofantenna feeds, such as, for example, electrically conductive tubes.

Referring now to FIGS. 4-5, a particularly advantageous embodimentincluding a patch antenna 40′ similar the patch antenna illustrated inFIG. 1, is illustrated in an electronic device 20′. The electronicdevice 20′ includes a substrate 21′ and a stacked arrangement of layers.A photovoltaic layer 60′ is above the substrate 21′. The photovoltaiclayer 60′ is illustratively a layer of solar cells. The photovoltaiclayer 60′ may include other types of photovoltaic cells or devices, aswill be appreciated by those skilled in the art.

The antenna ground plane 51′ is illustratively above the photovoltaiclayer 60′ and between the substrate 21′ and the patch antenna 40′. Theantenna ground plane 51′ is illustratively as a mesh so that it isoptically transmissive. The antenna ground plane 51′ may be copper, forexample. The antenna ground plane 51′ may be another type of conductivematerial, as will be appreciated by those skilled in the art. Theantenna ground plane 51′ is particularly advantageous because the solarcells of the photovoltaic layer 60′ are typically a relatively poorground plane.

The patch antenna 40′ is illustratively above the photovoltaic layer 60′and the antenna ground plane 51′. The patch antenna 40′ isillustratively a conductive mesh material or includes a conductive meshlayer 41′ that is also optically transmissive. The opticallytransmissive patch antenna 40′ and antenna ground plane 51′advantageously allow between about 51-52% of light through to thephotovoltaic layer 60′.

The dielectric layer 52′ between the antenna ground plane 51′ and thepatch antenna 40′ is also light-transmissive. The dielectric layer 52′may be glass. However, glass may be susceptible to increased breakageand may be relatively fragile. The dielectric layer 52′ may bepolystyrene. The dielectric layer 52′ may also be polycarbonate, whichexhibits increased RF dissipation, as will be appreciated by thoseskilled in the art.

The dielectric layer 52′ illustratively includes an anti-reflectivelayer 53 a′, 53 b′ on both sides thereof to reduce light reflection backaway from the photovoltaic layer 60′. Of course, the anti-reflectivelayer 53′ may be on one side of the dielectric layer 52′ and may be on aportion or portions of the dielectric layer.

The anti-reflective layer 53′ may be a quarter-wavelength thick withrespect to the desired light. The anti-reflective layer 53′ may includetitanium and/or fluorine. Of course, the anti-reflective layer 53′ mayinclude other types of materials.

Additionally, each anti-reflective layer 53′ may have a permeabilitythat is within about ±10% of the permittivity. This may advantageouslyallows light to pass through regardless of color or wavelength.

As will be appreciated by those skilled in the art, light passingthrough the patch antenna 40′, the dielectric layer 52′, and the antennaground plane 51′ to the photovoltaic layer 60′ is converted toelectrical energy. The converted electrical energy from the photovoltaiclayer 60′ may be used to power the wireless circuitry 34′, for example.

A prior art ground plane antenna, for example, is typically a solidsquare of metallic material with radiating elements over a ground plane.Thus, light cannot pass through, which may make it increasinglydifficult to combine the functionality of a photovoltaic layer with apatch antenna to achieve desired antenna characteristics.

Indeed, combination of a patch antenna and photovoltaic layer,including, for example, a solar cell may be particularly advantageous insatellite communications. More particularly, a combined antenna andphotovoltaic layer device may reduce surface area of a satellite, andthus launch costs. For example, year 2000 launch costs were about$11,729.00 per pound. A solar cell, which is mostly silicon, weighsabout 5803 pounds per cubic meter, and are about 0.002 meters thick.Thus, a solar cell weighs about 15 pounds per square meter, thus givinga launch cost of $176,000.00 per square meter for solar cells. Thus, anyreduction is overall weight advantageously translates into a reducedcost.

Referring now to FIGS. 6-7, another particularly advantageous embodimentof the patch is illustrated in an electronic device 20″. The electronicdevice 20″ is illustratively a mobile wireless communications device andincludes input devices 33″ or keys and a display 32″ carried by thehousing 31″. The electronic device 20″ includes a substrate 21″ and astacked arrangement of layers (FIG. 7). A visual display layer 70″ isabove the substrate 21′. The visual display layer 70″ is illustrativelya liquid crystal display (LCD). The visual display layer 70″ may beanother type of light emitting or light modulating visual display, aswill be appreciated by those skilled in the art.

The antenna ground plane 51″ is illustratively above the visual displaylayer 70″ and between the substrate 21″ and the patch antenna 40″. Theantenna ground plane 51″ is illustratively also as a mesh so that it isoptically transmissive to allow the visual display layer 70″ to be seentherethrough. In some embodiments, the antenna ground plane 51″ may beomitted, as the visual display layer 70″ may include or be sufficient asthe ground plane.

The patch antenna 40″ is illustratively above the visual display layer70″ and the antenna ground plane 51″. The patch antenna 40″ isillustratively a conductive mesh material or includes a conductive meshlayer 41″ that is also optically transmissive.

The dielectric layer 52″ between the antenna ground plane 51″ and thepatch antenna 40″ is also light-transmissive. The dielectric layer 52″may be plastic, for example, and may be part of the housing 31″ of thewireless communications device 20″. More particularly, the dielectriclayer 52″ may be the clear plastic layer of a wireless communicationsdevice housing 31″ that typically covers the visual display layer 70″,or LCD.

The dielectric layer 52″ may also include an anti-reflective layer 53a″, 53 b″ on both sides thereof to reduce light reflection back awayfrom the visual display layer 70″. Of course, the anti-reflective layer53″ may be on one side of the dielectric layer 52″ and may be on aportion or portions of the dielectric layer.

As will be appreciated by those skilled in the art, light passingthrough the patch antenna 40″, the dielectric layer 52″, and the antennaground plane 51″ from the visual display layer 70″ advantageously allowsa user to see the visual display layer, while including thefunctionality of the patch antenna. Thus, the overall size increase ofthe electronic device for the stacked arrangement of layers isrelatively small.

Referring now to the graphs 71, 72, 73, 74, 75 in FIGS. 8-11, aprototype electronic device was formed and included the patch antennahaving an electrically conductive and optically transmissive meshantenna patch layer, the optically transmissive dielectric layer, andthe optically transmissive antenna ground plane also having anelectrically conductive mesh layer. The prototype electronic device hasthe parameters, for example, size, listed below in Table 1.

TABLE 1 Parameter Specification Basis Size 2.25″ × 2.25″ × 0.27″Measured Weight 25 grams Measured Center Operating 1575.42 MHz Specified Frequency (GPS L1) Realized Peak Gain  1598 MHz MeasuredFrequency Realized Gain   3.73 dBic Simulated for Realized Gain  −0.1dBic Measured Half Power 88 degrees Simulated for Beamwidth RadiationPattern Single petal rose, Simulated for broadside to antenna plane 3 dBGain   99 MHz Simulated for Bandwidth 3 dB Gain   129 MHz MeasuredBandwidth Impedance 50 ohms nominal Specified Polarization Right handcircular Specified Polarization Axial <0.3 dB Measured Ratio BeamForming 0, 90 degree Implemented Network hybrid divider Antenna PatchBrass screen of Implemented Material fine wire Reflector Material Gold -Molybdenum Implemented fabric Substrate Lexan ™ ImplementedPolycarbonate Substrate Relative 2.94 dimensionless Handbook DielectricConstant (RF) Substrate Optical 88% Handbook Transmission Total Light52% Measured Transmission Through The Antenna, normal incidence CurrentTraveling Wave or Simulated for Distribution nearly so

It should be noted that simulated data in Table 1 assumed perfectloss-less materials, while the measured data was taken from a physicalprototype having materials with heat losses. With respect to thedifferences between the measured and simulated losses for the prototype,the losses from the polycarbonate, i.e. optically transmissivedielectric layer, may be attributed to the polycarbonate not beingvended as a microwave printed wire board, or dielectric, material. Thepolycarbonate actual loss tangent was higher than listed in the table.Replacement of the polycarbonate with a polystyrene material mayincrease performance by reducing losses. A polycarbonate substrate wasused for its high impact resistance and was relatively efficient enoughto permit GPS reception.

Additionally, the coaxial cable and power divider was not simulated.With respect to the ground plane layer, which was a brass mesh orscreen, the measured results include contact resistances, directionalbias, and mechanical tolerances, which were not captured by simulation.

Referring particularly to the Smith Chart 71 in FIG. 8, the two curls ofthe impedance response 76 indicate that the patch antenna has a doubletuned Chebyschev polynomial behavior. A Chebyschev behavior isrelatively good for bandwidth, as it is about four-time that of aquadratic and/or single tuned response, for example.

The realized gain of the physical prototype was measured on an antennarange. Referring now to the graph 73 in FIG. 10, the measured realizedgain response over frequency is illustrated. This may be referred to asa swept gain measurement. The data was taken at the look angle ofradiation pattern peak amplitude, which was broadside or normal to theantenna physical plane. The method used was the gain comparison methodor substitution method, and a thin wire half wave dipole was used as thegain standard which is known to have a gain of 2.1 dBil.

The reference dipole gain is illustrated by line 81, and the realizedgain at each of the antenna feeds is illustrated by lines 82 and 83.There were two antenna feed ports on the hybrid: one providing righthand circular polarization and the other left hand circularpolarization. The prototype reception was 5.2 dB down from the half wavedipole. Applying the Substitution Method: Measured Patch AntennaGain=Reference Dipole Gain+Polarization Loss Factor+The Difference InTransmission Loss=2.1+3.0+(−5.2)=−0.1 dBic.

The polarization loss factor arises from the fact that the source dipolewas linearly polarized, and the antenna under test was circularlypolarized. The polarization loss factor for a linearly polarized antennareceiving circular polarization is 3 dB. The measured realized gainincludes the loss mechanisms that accompany real world antennas, suchas, for example, materials heating and VSWR. Where lines 82, 83 overlapthe polarization of the prototype was substantially or nearly perfectlycircular so near perfect circular polarization was realized near 1610MHz.

The graph 74 in FIG. 11 is an elevation plane radiation pattern cutobtained by numerical electromagnetic simulation, and it illustratesthat the half power beamwidth is 88 degrees. The radiation pattern lobeis broadside, e.g. the beam is normal to plane that the antenna lies inand there is a radiation pattern minima in the antenna plane. FIG. 8 wascalculated using an infinite ground plane so there are no side lobes orbacklobes in the plot.

Another prototype electronic device was formed and further included thephotovoltaic layer. The prototype electronic device was tested for DCpower production. The photovoltaic layer included a series wired stringof six model XOB 17-12 XI Solar Cells as manufactured by IXYSCorporation of Milpitas, Calif. Standing alone, the solar cell stringprovided 2.9 volts at 362 milliamperes in relatively bright sunlight.When included as part of the prototype electronic device, the measuredcurrent output was 18.4 milliamperes at nearly the same voltage. Thus,50 percent of the un-shaded power output was obtained. As will beappreciated by those skilled in the art, the patch antenna provided abeneficial trade of wireless transmission and reception while permittinguseful solar power production from the same surface area, and increasedlevels of DC power output may be obtained. While an optical coating wasnot used in the prototype electronic device, it may be used inconjunction with any of the layers. Additionally, a relatively finerconductive mesh may also be used.

During the solar power testing no photosensitivity of the patch antennawas noted. In other words, neither the solar cells nor sunlight affectedthe tuning of the patch antenna.

A method aspect is directed to a method of making an electronic device20. The method includes forming a patch antenna 40 to be carried by asubstrate 21 and to include an electrically conductive mesh 41 layerhaving a perimeter defined by a plurality of perimeter segmentscomprising two pair of arcuate perimeter 42 a-42 d segments with a cusptherebetween 43 a-43 d. The method also includes coupling at least oneantenna feed 44 to the patch antenna.

Another method aspect is directed to a method of making an electronicdevice 20′. The method includes forming a stacked arrangement of layerson a substrate 21′ by at least positioning a photovoltaic layer 60′above the substrate 21′, and positioning an antenna ground plane 51′above the photovoltaic layer 60′. The antenna ground plane 51′ includesa first electrically conductive mesh layer being optically transmissive.Forming the stacked arrangement also includes positioning a patchantenna 40′ above the photovoltaic layer 60′ that includes a secondelectrically conductive mesh layer being optically transmissive.

Yet another method aspect is directed to a method of making anelectronic device 20″. The method includes forming a stacked arrangementof layers on a substrate 21″ by at least positioning a patch antenna 40″above a visual display layer 70″. The patch antenna 40″ includes anelectrically conductive mesh that is optically transmissive.

Further details of electronic devices including a patch antenna may befound in co-pending applications GCSD-2373, and GCSD-2380, which areassigned to the assignee of the present application, and the entirecontents of all of which are herein incorporated by reference. Manymodifications and other embodiments will come to the mind of one skilledin the art having the benefit of the teachings presented in theforegoing descriptions and the associated drawings. Therefore, it isunderstood that the disclosure is not to be limited to the specificembodiments disclosed, and that modifications and embodiments areintended to be included.

1. An electronic device comprising: a substrate and a stackedarrangement of layers thereon comprising a photovoltaic layer above saidsubstrate, an antenna ground plane above said photovoltaic layer andcomprising a first electrically conductive optically transmissive meshlayer, and a patch antenna above said photovoltaic layer and comprisinga second electrically conductive optically transmissive mesh layer. 2.The electronic device according to claim 1, further comprising anoptically transmissive dielectric layer between said antenna groundplane and said patch antenna.
 3. The electronic device according toclaim 2, further comprising at least one anti-reflective layer on saidoptically transmissive dielectric layer.
 4. The electronic deviceaccording to claim 1, wherein said patch antenna has a perimeter definedby a plurality of perimeter segments comprising at least one pair ofarcuate perimeter segments with a cusp therebetween.
 5. The electronicdevice according to claim 4, wherein said at least one pair of arcuateperimeter segments are inwardly extending.
 6. The antenna assemblyaccording to claim 1, wherein said patch antenna is planar.
 7. Theelectronic device according to claim 1, further comprising at least oneantenna feed coupled to said patch antenna.
 8. The electronic deviceaccording to claim 7, said at least one antenna feed comprises a pair ofantenna feeds operable to provide a non-linear polarization.
 9. Theelectronic device according to claim 1, wherein said second electricallyconductive optically transmissive mesh layer comprises a flexibleinterwoven electrically conductive mesh layer.
 10. The electronic deviceaccording to claim 1, wherein said second electrically conductiveoptically transmissive mesh layer comprises a body portion and a hemportion coupled thereto.
 11. An electronic device comprising: asubstrate and a stacked arrangement of layers thereon comprising aphotovoltaic layer above said substrate, an antenna ground plane abovesaid photovoltaic layer and comprising a first electrically conductiveoptically transmissive mesh layer, a patch antenna above saidphotovoltaic layer and comprising a second electrically conductiveoptically transmissive mesh layer, and an optically transmissivedielectric layer between said antenna ground plane and said patchantenna; and wireless circuitry powered by said photovoltaic layer andcoupled to said patch antenna.
 12. The electronic device according toclaim 11, further comprising at least one anti-reflective layer on saidoptically transmissive dielectric layer.
 13. The electronic deviceaccording to claim 11, wherein said patch antenna has a perimeterdefined by a plurality of perimeter segments comprising at least onepair of arcuate perimeter segments with a cusp therebetween
 14. Theelectronic device according to claim 13, wherein said at least one pairof arcuate perimeter segments are inwardly extending.
 15. The electronicdevice according to claim 11, wherein said second electricallyconductive optically transmissive mesh layer comprises a flexibleinterwoven electrically conductive optically transmissive mesh layer 16.A method of making an electronic device comprising: forming a stackedarrangement of layers on a substrate by at least positioning aphotovoltaic layer above the substrate, positioning an antenna groundplane above the photovoltaic layer and comprising a first electricallyconductive optically transmissive mesh layer, and positioning a patchantenna above the photovoltaic layer and comprising a secondelectrically conductive optically transmissive mesh layer.
 17. Themethod according to claim 16, wherein forming the stacked arrangementfurther comprises positioning an optically transmissive dielectric layerbetween the antenna ground plane and the patch antenna, the dielectriclayer.
 18. The method according to claim 17, wherein forming the stackedarrangement further comprises forming at least one anti-reflective layeron the optically transmissive dielectric layer.
 19. The method accordingto claim 16, wherein the patch antenna has a perimeter defined by aplurality of perimeter segments comprising at least one pair of arcuateperimeter segments with a cusp therebetween.
 20. The method according toclaim 16, wherein the second electrically conductive opticallytransmissive mesh layer comprises a flexible interwoven electricallyconductive optically transmissive mesh layer.